Blog appearance/design

My campaign blog Voice of the candidate is up and running. I would like to do some tweaks that would improve the overall appearance and readability. So, how do I do the following:

• I want to have a uniform color background for the banner. How can I get rid of the green border?
• I want to change the default font and color so that the text is more readable. Right now, it appears that I have to change the font of each paragraph by hand. If I just change the font at the beginning of a post, it reverts to the default after the end of a paragraph.

Thanks…